Optical spray pattern imaging apparatus for generating images including density image features

ABSTRACT

A spray pattern imaging apparatus, and method of operation, is described herein. The method is carried out by the spray pattern imaging apparatus that includes a frame having a set of known aspects corresponding to a first dimension and a second dimension within a first plane. The spray pattern imaging apparatus also includes a light source generating a planar light pattern within a substantially same plane as the first plane of the frame. The set of known aspects facilitate both correcting an image distortion and a scaling of a spray pattern image generated by an image acquisition device during a spray application by a nozzle positioned in a physical relationship with the planar light pattern such that spray particles emitted from the spray nozzle pass through the planar light pattern while an initial image is acquired by the image acquisition device.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application claims the benefit of U.S. Provisional PatentApplication No. 62/842,964, filed May 3, 2019, which is incorporated byreference.

TECHNICAL FIELD

The present invention relates generally to spray pattern imagingapparatuses, and more particularly, to systems for acquiring andprocessing one or more spray pattern images to render a spray patternfor testing a combination of spray nozzle and sprayed material.

BACKGROUND

Spraying applications are characterized by a combination of spray nozzleconfiguration and sprayed material specification. The spray nozzleconfiguration comprises one or more spray nozzles configured in athree-dimensional space—including both distance and directioncharacteristics. The sprayed material specification comprises one ormore sprayed materials (mixed at particular ratios) having particularfluid characteristics—including viscosity, surface tension, volatility,etc.).

Users of such systems have a strong interest in ensuring that aparticular spraying application will provide a particular desiredcoverage—e.g., both complete coverage and even distribution of aparticular desired amount. Highly complex systems provide suchinformation using high precision measuring devices that carry outtesting and/or optimization offline and in a controlled setting. Suchsystems are both extremely expensive and require complex testingprocedures that may take days or even weeks to complete. While suchknown systems are highly desirable, their cost and complexity maypreclude their use a vast number of spraying applications that requirefield configuration—literally in a farm field, in a factory/productionplant, in a shop, etc.

SUMMARY

Embodiments of the present invention provide a spray pattern imagingapparatus that includes a frame having a set of known aspectscorresponding to a first dimension and a second dimension within a firstplane. The spray pattern imaging apparatus also includes a light sourcegenerating a planar light pattern within a substantially same plane asthe first plane of the frame. The set of known aspects facilitate bothcorrecting an image distortion and a scaling of a spray pattern imagegenerated by an image acquisition device during a spray application by anozzle positioned in a physical relationship with the planar lightpattern such that spray particles emitted from the spray nozzle passthrough the planar light pattern while an initial image is acquired bythe image acquisition device.

Moreover, embodiments of the claimed invention are directed to a methodfor rendering a spray pattern image, by a spray pattern imagingapparatus comprising a frame having a set of known aspects correspondingto a first dimension and a second dimension within a first plane; and alight source generating a planar light pattern within a substantiallysame plane as the first plane of the frame. The method carried out bythe apparatus includes acquiring, by an image acquisition device, aninitial spray pattern image data during a spray application by a nozzlepositioned in a physical relationship with the planar light pattern suchthat spray particles emitted from the spray nozzle pass through theplanar light pattern. The method further includes processing the initialspray pattern image data, using the set of known aspects to facilitateboth correcting an image distortion and a scaling of the initial spraypattern image to render a corrected and scaled spray pattern image.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B provide perspective views of two illustrative examplesof a system embodying the current invention;

FIGS. 2A, 2B, and 2C are additional views of the systems illustrativelydepicted in FIGS. 1A and 1B;

FIGS. 3A, 3B, 3C and 3D depict exemplary user interfaces for importingand selecting an image data (or portion thereof) acquired by an imageacquisition device of the system depicted in FIGS. 1 and 2;

FIGS. 4A and 4B are illustrative grey scale images (from a colorizedoriginal) depicting both an extent and a density of a spray pattern,rendered from data acquired by the system depicted in FIGS. 1A, 1B, 2Aand 2B;

FIG. 5 is an exemplary view of a comparision rendered by the system andindicating a satisfactory observed spray pattern (in relation to areference image);

FIG. 6 is an exemplary view of a comparision rendered by the system andindicating a non-satisfactory observed spray pattern (in relation to areference image);

FIG. 7 is an exemplary view generated by combining multiple instances ofa single observed spray pattern image; and

FIG. 8 is a flow diagram illustrating processes and data flow activitiesexecuted during an illustrative procedure for acquiring a spray patternimage data, processing the spray pattern image data, and rendering animage from the processed spray pattern image data in keeping with theinvention.

While the invention is susceptible of various modifications andalternative constructions, a certain illustrative embodiment thereof hasbeen shown in the drawings and will be described below in detail. Itshould be understood, however, that there is no intention to limit theinvention to the specific form disclosed, but on the contrary, theintention is to cover all modifications, alternative constructions, andequivalents falling within the spirit and scope of the invention.

DESCRIPTION OF EMBODIMENTS

Illustrative examples are now described that address the need to providesatisfactorily precise and accurate observations, in the form of avisual image, of spray distribution in the field (as opposed to testlabs) and to carry out such observation with momentary feedback tousers' adjustments to nozzle configuration and/or sprayed materialproperties.

Referring to FIG. 1A, an illustrative spray distribution imaging system100 is depicted. The illustrative system has utility in a wide varietyof environments. However, the illustrative examples are particularlyuseful in the field or in situations where momentary spray patternfeedback to a current spraying application (configuration) is desired bya user. In the illustrative example, the system 100 includes a frame110. The frame 110 is rectangular in the illustrative example andincludes a set of legs (e.g. leg 120) disposed at each corner of therectangular frame, thus providing a gap between the frame 110 and asurface upon which the system 100 is placed. The known rectangular shapeof the frame 110 provides an important feature fornormalizing/correcting an initially acquired image. The known aspect ofthe frame 110 also applies to a known length of the distal edge 112 (orportion thereof) of the frame 110 (or either side edge) that may be usedto determine a distance of a feature within the initially acquiredimage.

Therefore, the known aspect of the frame 110 is not limited todimensions of a retangular shaped frame. Illustrative examples of thepresent disclosure may be any of a variety of shapes and configurations.For example, the frame 110 may be circular in shape. Moreover, anycombination of visual features, having known physical dimensions (in atwo-dimensional plane), indicated by the frame 110 are contemplated inmeeting the “known aspect” of the frame 110. As such, in yet otherexamples, the frame 110 may have almost any shape as long as there are aset of visual features (e.g. corners, notches, markings) that arevisually identifiable in a camera field of view to facilitate, within acaptured camerat image, at least: (1) correction of optical distortion(e.g. paralax) and (2) scale (determine two-dimensional sizing of) sprayimage features. Thus, in accordance with illustrative examples of theframe 110, the relative positions of the visually identifiable markingson the frame in a spray pattern image are used to correct for distortionand determine dimensions of spray pattern features.

Additionally, it is further noted that the frame 110 (with knownaspects) need only be present during an initial calibration and/orconfiguration stage of operation of the system 100. Once a field of viewof a camera in relation to an illuminated plane of a spray field ofinterest is established and fixed, the frame 110 may be withdrawn duringsubsequent acquisition of spray pattern (illuminated in a plane by LASERlight source(s)).

A holder 130, which is optional (as shown in the system depicted in FIG.1B), is mounted upon the frame 110. The holder 130 includes a gripstructure that engages and holds a smart phone 140 (or other digitalimage acquisition device) in a stable/fixed relation to the frame 110(i.e. to provide a steady image). In the illustrative example, theholder 130 is adjustable (via linear and pivoting adjustments) to enablepositioning and orienting an imaging lens of the smart phone 140 inrelation to a plane defined by edges of the frame 110.

With continued reference to FIGS. 1A and 1B, a planar light source (notshown) emits a planar light pattern 150 in the plane defined by theedges of the frame 110. A battery pack 160 (or any suitable powersupply) is provided to power the planar light source. In an illustrativeexample, the planar light source is provided by passing an output beamof a laser (e.g. a green laser, however other types of laser may also beused) through a diffraction grating to provide a suitably evendistribution of light intensity in the planar light pattern 150. The useof a monochromatic (e.g. green) laser as the light source facilitatesusing the corresponding (green) data element of the initially acquiredcolor image of the spray field to determine a spray density at aparticular pixel location in the initially acquired image. A widevariety of planar light sources (not limited to a monochromatic/laser)are contemplated in various examples of the present disclosure.

In cases where a non-uniform distribution cannot be achieved, a suitablecompensation factor can be applied to compensate for the variations inintensity. For example, a compensation factor may be applied accordingto an azimuthal angle from a point of the planar light source.

Moreover, the present disclosure contemplates additional forms of(programmed image processor implemented) compensating for light sourceeffects, including compensating for viewing angle of a camera aperture(receiving the droplet scattered light from the planar light patterngenerated by the planar light source) with respect to the source of theplanar light pattern. Referring to FIG. 1B, for example, a scatteredlight intensity correction may be applied to account for a variation ofintensity of scattered light received by the camera aperture based upona relative scattering angle of light across the planar light pattern fora known position of the camera aperture in relation to a direction ofthe light emitted by the planar light source. By way of illustrativeexample, in FIG. 1B, a camera aperture is positioned such that aleft-side of a wide-angle spray pattern is nearly in-line with rays oflaser light emitted by the light source (at the far edge of the frame).On the other hand, the right-side of the wide-angle spray pattern isillumated by light from the laser that is initially emitted relativelyaway from the camera. Therefore, a relatively large scattering angle isfollowed by the light on the right-side of the wide angle spray patternthat is received by the camera aperture.

The camera aperture position effect discussed above, as well as anyother light source and/or aperture view effects, may range fromnegligible to severe depending on the planar light sheet source type(point vs planar), and relative distance from the source to the sprayregion.

The system 100 includes a programmed processor element that is, forexample, incorporated into the smart phone 140—e.g. in the form an “app”program downloaded and maintained/executed on the smart phone 140. Theprogrammed processor element is configured with computer-executableinstructions that are executed by a processor of the smartphone to carryout operations of a method that is summarized by way of example in FIG.7 (described herein below). In other illustrative examples, theprogrammed processor element is provided in any of a variety ofcomputing devices, including tablet, notebook, and desktop computersystems.

Turning to FIGS. 2A and 2B, two alternative views are provided of thesystem 100 depicted in FIG. 1A. In these two views, the battery powerpack 160 is replaced by a continous power supply (plugged into thesystem 100). The structure of the holder 130 (illustrative example)includes a repositionable mounting 170 that facilitates sliding theholder along an edge 180 of the frame 110.

Turning to FIG. 2C an additional view is provided of the system depictedin FIG. 1B that shows a illustrative example of using the system 100without a fixed holder such as the holder 130 depicted in FIGS. 2A and2B. This version illustrates the utility of the “known aspects” of theframe 110 that facilitates providing a distortion correction/scalingsource for each image—regardless of the position/orientation of thecamera that acquires the image. In each captured image, the “knownaspect” of the frame (captured within the image containing the capturedspray pattern) facilitates performing an image distortion correction andscaling.

Turning to FIGS. 3A and 3B, two exemplary views of a captured sprayimage (displayed on an exemplary user interface) are provided. In theview provided in FIG. 3A, a captured spray image is displayed on a userinterface that simultaneously displays the “known aspects” (i.e. a widthof 11 inches and a length of 15 images) of the frame 110. The positionsof the corners of the frame 110 and the known dimensions and shape ofthe frame 110 are used to correct image distortion and to scale thecaptured spray pattern within an imaging plane (defined by a planarlight source generated in a substantially same plane as a plane definedby the frame 110. In FIG. 3B, the spray has been spatially corrected fordistortion arising from the camera view angle.

Turning to FIGS. 3C and 3D, an exemplary set of user interfaces,supported by the above mentioned app on the smart phone 140, enable auser to select a portion of a previously acquired image, which may beany type of image including both single static image (jpeg) frame, movie(mpeg) frame, time-lapse sequential image frame sets—such as those nowsupported by a “live” photo option on smart phones that acquire/storemultiple sequential images in response to a single user “click” of aview. In the illustrative view, an import data field supports userselection of an image file for processing/viewing and designating anexport data destination for the data. Additionally, an edit image fieldincludes an image display sub-region and controls that enable a user toselect a portion of a displayed image frame that will be the subject offurther processing and/or storing. In the illustrative example, acontrol enables a user to “frame” the rectangle area of interest in thesource image—for subsequent processing/saving by the system 100.

The system 100 supports acquiring, processing a variety of image datasources captured by a variety of camera types. In addition to staticimages, the system 100 contemplated acquiring, processing and displayinglive (i.e. substantially real time) video. As such a wide variety oftypes of image/images generated by the system 100 are contemplated inaccordance with various illustrative examples described herein.

Turning to FIGS. 4A and 4B, two illustrative/exemplary views areprovided of exemplary output (processed) image display interface,including an exemplary output image. In the illustrative example, theuser interface supports user specification of units(inches/millimeters); contour (density) colors (including grey shadesinstead of color); and axis (image field of interest) limits. In theuser interface depicted in FIG. 4B, a refresh button causes the system100 to recalculate an output image based upon the selected parametersand display the image in the “Spray Distribution” field of the exemplarydisplay. Thus, the “edit image” controls enable a user to configurablydesignate a part of an imported photographic image for furtherprocessing, analysis and display. In another illustrative output view,provided in FIG. 4A, the refresh button is not provided. Instead, theview updates the user/displayed view in response to a change inavailable displayed image (e.g. a new captured image, a user adjustmentto a display parameter in an existing/displayed image, etc.).

Turning to FIG. 5, an illustrative example is provided of a type ofanalysis performed by the system 100 on a processed image (i.e. one thathas been transformed into a graphical representation of overall coveragewith displayed/distinguished regions of differing spray density. Ameasured spray pattern image 500 is depicted. The measured spray patternimage 500 includes an overall coverage area outline 505 that bounds acolorized (grey shaded) region that corresponds to the subregions ofvarying spray density. A reference spray pattern image 510 is depictedthat is generated from a database (i.e. the expected pattern). Thereference spray pattern image 510 includes an overall coverage areaoutline 515 that bounds a colorized (grey shaded) region thatcorresponds to the subregions of varying spray density. In theillustrative example, the measured image 500 is compared to thereference image 510 (either by the user or via a criteria-drivenautomated comparison executed on the smart phone 140 using the appprogram code executed by the processor. Since the coverage areas of thereference image 510 and the measured image 500 are substantiallysimilar, the analysis renders a positive result (i.e. the sprayapplication is properly configured).

On the other hand, FIG. 6 depicts a potential way of depicting anegative comparison result. In this case, a measured image 600 includesa measured coverage outline 605 that does not sufficiently track areference outline 610. The outlines, by way of example, are carried outin an automated manner by the system 100. The programmed processor ofthe smart phone 140 detects the unacceptable deviation of the comparedoutlines and renders an negative result. In yet another view, thereference and measured images are compared and any resulting differencesare represented by a two-dimensional colorized image depicted thedifferences where, for example, green means no difference, yellow meansa slight difference, and red indicates a significant difference.

Turning to FIG. 7, two exemplary views are provided. An “IndividualSpray Controls” view depicts a scan image for a single spray nozzleacquired by the system 100. A rotation control enables a user to rotatethe scan image up to 180 degrees. An “Individual Spray Limits” interfacepermits a user to define image limits for display/clipping of an inputprocesses image. Turning to a “composing” feature, a composition imageis depicted in the “Overlay Spray Controls” view. The composition imageis created by a user specifying an input single nozzle image (e.g. theone depicted in the “Individual Spray Controls” view), specifying anumber of nozzles (e.g. 15), a number of rows (e.g. 1), a gap betweenadjacent nozzles in a row (e.g. x=6 mm) and a column (e.g., 100 mm). Inthe illustrative example, the overlay composite image is a singlecomposite row consisting of overlapping images generated from 15 nozzlesseparated by 6 mm. Additionally, two summation views (x-direction andy-direction) are provided for depicting accumulated (summed) spraydensity in the x and y directions, respectively.

Turning to FIG. 8, a flowchart summarizes the overall operation of thedata acquisition and image processing/analysis operations performed bythe system 100. During 800, an initial image data is acquired. In theillustrative system 100, a nozzle is positioned above the frame 110. Assprayed material passes from the nozzle and through the planar lightpattern 150, an initial image data is acquired. As noted above, variousforms of acquired images are contemplated including single static images(e.g. jpeg), a stream of live images (automatic high-repetition ratephoto image function of smart phones), and movie image data (e.g. mpeg).The initial image (intensity) data includes red, green, and bluecomponents. However, only the component corresponding to the color ofthe source laser (e.g. green) is used in later processing.

While a single image frame may be acquired during 800, it is preferableto acquire several frames and then average the pixel intensity values atcorresponding locations across multiple image frames during 810. In theillustrative example, the “green” intensity component of correspondingpixel values is averaged across multiple frames.

During 820, the averaged image pixel intensity values rendered during810 are corrected. In an illustrative example, the edges of the frame110 are used to correct for parallax and any other distortions arisingfrom the lens of the smart phone 140. The positions of the pixels arecorrected in a two-dimensional space according to corrections needed to“straighten” the edges of the frame 110 (including ensuring the cornersare 90 degrees). Additionally, intensity values are corrected, in anembodiment, to compensate for the decreased intensity of light basedupon distance from the source and azimuthal angle position from thesource.

During 830, the image is normalized by applying scalar value topositions on the image plane. The image scaling is intended tocompensate for magnification/zooming during image acquisition by a user.In an illustrative example, a known length of one or more edges of theframe are used to determine a proper scaling value for normalizing theimage data positions of the image data rendered by step 820.

During 840, intensity values of the various normalized intensity imagedata rendered during step 830 are applied to a binning function thatassigns a discrete value in a limited range (e.g. 1 to 10) based uponthe intensity value at the particular normalized pixel location. Thus,the output of 840 is a corrected, normalized, discrete density-codedimage data.

During 850, the corrected, normalized, discrete density-coded image datais stored, for example, in a memory of the smart phone 140. Thereafter,a user selects the stored data for purposes of viewing in accordancewith the various user interfaces depicted in FIGS. 4A, 4B, 4C, 5, 6, and7. A user-selected color mapping scheme is thereafter used to render acolorized (or gray scale) image of the coverage area and densitycharacteristics of the measured spray application.

It will be appreciated that the foregoing description relates toexamples that illustrate a preferred configuration of the system.However, it is contemplated that other implementations of the inventionmay differ in detail from foregoing examples. As noted earlier, allreferences to the invention are intended to reference the particularexample of the invention being discussed at that point and are notintended to imply any limitation as to the scope of the invention moregenerally. All language of distinction and disparagement with respect tocertain features is intended to indicate a lack of preference for thosefeatures, but not to exclude such from the scope of the inventionentirely unless otherwise indicated.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the invention (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. The terms “comprising,” “having,” “including,” and “containing”are to be construed as open-ended terms (i.e., meaning “including, butnot limited to”) unless otherwise noted. Recitation of ranges of valuesherein are merely intended to serve as a shorthand method of referringindividually to each separate value falling within the range, unlessotherwise indicated herein, and each separate value is incorporated intothe specification as if it were individually recited herein. All methodsdescribed herein can be performed in any suitable order unless otherwiseindicated herein or otherwise clearly contradicted by context. The useof any and all examples, or exemplary language (e.g., “such as”)provided herein, is intended merely to better illuminate the inventionand does not pose a limitation on the scope of the invention unlessotherwise claimed. No language in the specification should be construedas indicating any non-claimed element as essential to the practice ofthe invention.

Accordingly, this invention includes all modifications and equivalentsof the subject matter recited in the claims appended hereto as permittedby applicable law. Moreover, any combination of the above-describedelements in all possible variations thereof is encompassed by theinvention unless otherwise indicated herein or otherwise clearlycontradicted by context.

What is claimed is:
 1. A spray pattern imaging apparatus comprising: aframe having a set of known aspects corresponding to a first dimensionand a second dimension within a first plane; and a light sourcegenerating a planar light pattern within a substantially same plane asthe first plane of the frame; wherein the set of known aspectsfacilitate both correcting an image distortion and a scaling of a spraypattern image generated by an image acquisition device during a sprayapplication by a nozzle positioned in a physical relationship with theplanar light pattern such that spray particles emitted from the spraynozzle pass through the planar light pattern while an initial image isacquired by the image acquisition device.
 2. The spray pattern imagingapparatus of claim 1, wherein the frame is rectangular.
 3. The spraypattern imaging apparatus of claim 1, wherein the set of known aspectscomprise a length dimension and a width dimension.
 4. The spray patternimaging apparatus of claim 3, wherein one or both the length dimensionand the width dimension are defined by an inside edge of the frame. 5.The spray pattern imaging apparatus of claim 3, wherein one or both thelength dimension and the width dimension are indicated by a marking onthe frame.
 6. The spray pattern imaging apparatus of claim 1, whereinthe light source is a laser.
 7. The spray pattern imaging apparatus ofclaim 1, wherein the spray pattern imaging apparatus further comprises aholder for holding the image acquisition device during the sprayapplication in a fixed relationship with respect to the planar lightpattern.
 8. The spray pattern imaging apparatus of claim 7, wherein theholder is fixed to the frame.
 9. The spray pattern imaging apparatus ofclaim 7, wherein the holder is not fixed to the frame during operation,thereby facilitating removing the frame from a field of view of theimage acquisition device after an image calibration operation based uponthe known aspects of the frame positioned such that the first plane issubstantially co-planar with the planar light pattern.
 10. The spraypattern imaging apparatus of claim 1 further comprising a programmedimage processor that operates to correct the spray pattern image forlight source position effects.
 11. The spray pattern imaging apparatusof claim 10 wherein the light source position effect arises from aviewing angle of an aperture of the image acquisition device withrespect to an angle of emission of scattered light from the lightsource.
 12. A method for rendering a spray pattern image, by a spraypattern imaging apparatus comprising: a frame having a set of knownaspects corresponding to a first dimension and a second dimension withina first plane; and a light source generating a planar light patternwithin a substantially same plane as the first plane of the frame,wherein the method comprises: acquiring, by an image acquisition device,an initial spray pattern image data during a spray application by anozzle positioned in a physical relationship with the planar lightpattern such that spray particles emitted from the spray nozzle passthrough the planar light pattern; and processing the initial spraypattern image data, using the set of known aspects to facilitate bothcorrecting an image distortion and a scaling of the initial spraypattern image to render a corrected and scaled spray pattern image. 13.The method of claim 12, wherein the set of known aspects comprise alength dimension and a width dimension.
 14. The method of claim 13,wherein one or both the length dimension and the width dimension aredefined by an inside edge of the frame.
 15. The method of claim 13,wherein one or both the length dimension and the width dimension areindicated by a marking on the frame.
 16. The method of claim 12, whereinthe light source is a laser.
 17. The method of claim 12, wherein thespray pattern imaging apparatus further comprises a holder for holdingthe image acquisition device during the spray application in a fixedrelationship with respect to the planar light pattern.
 18. The method ofclaim 17, wherein the holder is fixed to the frame.
 19. The method ofclaim 17, wherein the holder is not fixed to the frame during operation,thereby facilitating removing the frame from a field of view of theimage acquisition device after an image calibration operation based uponthe known aspects of the frame positioned such that the first plane issubstantially co-planar with the planar light pattern.
 20. The method ofclaim 12 further comprising a programmed image processor that operatesto correct the spray pattern image for light source position effects.21. Method of claim 20, wherein the light source position effect arisesfrom a viewing angle of an aperture of the image acquisition device withrespect to an angle of emission of scattered light from the lightsource.